londoneater.com — So here's how it works: Get a pre-paid card (in-store) and top up with cash. Go to one of the machines, each focusing on a style or region (featuring a total of 80 wines at any one time) and make your selection. Press for either one sip. Each 'sip' is roughly a shot glass, or 25ml. Sniff, swirl, whirl. Spit or swallow